Tsunami may have hit East Coast earlier in June

[Ginx snewx]

they've been documented to happen with as little as a 2mb rise/fall. it's not just the pressure relation though. it's the timing of the system relative to the wave period to keep the energy pumping into the long waves that's most important...that's why they are pretty rare. it takes a pretty well-aligned set of circumstances to happen. but some of them around the globe have actually been destructive.

its beyond cool to me, wish there was video

[Tropopause_Fold]

its beyond cool to me, wish there was video

i have video. just haven't had the time to compile it and make it nice. 

[Ginx snewx]

i have video. just haven't had the time to compile it and make it nice.

sweet look forward to it

[Ginx snewx]

several pressure rise fall couplets I found in a small quick check, also some interesting tidal stuff, looks like the big pond was sloshing.

[Tropopause_Fold]

i doubt the correctness of those graphs. 

[Ginx snewx]

i doubt the correctness of those graphs. 

help me here, oh yikes, missed the drama. Yea lots of other graphs showing gravity wave sigs. I also saw plots with the sea swell switching abruptly from ssw to due north back to ssw in an hour, that rarely occurs

[CT Rain]

Can't we all get along

[Tropopause_Fold]

Can't we all get along

i just can't help myself. 

[Typhoon Tip]

I still haven't seen anything that conclusively eliminates this as atmosphere or geologically attributed. 

 

I agree that seismology would be useful, but given the fact that the Earth is ringing like a bell most of the time, would a deep water landslides necessarily be detectable above the din of ordinary events ?   

 

It could be coincident timing just the same.  The articles state that surveying the continental shelf would need to be done to remove at least that as a possible cause.  

 

Waters in harbors have been known to recede due to strong off-shore flow.  If that were the case here, and then said flow were to abruptly relax, than flow back could be misconstrued as a tsunamis.   But, they are also talking about this being registered in Puerto Rico ... This derechio must have come from the planet Jupiter !

[Ginx snewx]

I still haven't seen anything that conclusively eliminates this as atmosphere or geologically attributed. 

 

I agree that seismology would be useful, but given the fact that the Earth is ringing like a bell most of the time, would a deep water landslides necessarily be detectable above the din of ordinary events ?   

 

It could be coincident timing just the same.  The articles state that surveying the continental shelf would need to be done to remove at least that as a possible cause.  

 

Waters in harbors have been known to recede due to strong off-shore flow.  If that were the case here, and then said flow were to abruptly relax, than flow back could be misconstrued as a tsunamis.   But, they are also talking about this being registered in Puerto Rico ... This derechio must have come from the planet Jupiter !

I have questions too, especially the reports from PR. I mean if this was localized to the NE I would understand.

[Tropopause_Fold]

I have questions too, especially the reports from PR. I mean if this was localized to the NE I would understand.

it could have been an asteroid for all i know. or some fat dude doing a cannonball. but i don't flatly dismiss what the data is best suggesting.

 

if it was an offshore slump, i would think the effects would have made it into the Gulf of Maine...and been felt down along the SE coast. but once you get north of Chatham, there's nothing. and spots like Bar Harbor are just as exposed to the SE as Chatham is (for waves moving from offshore to the west).

 

likewise, if you review the data out the SC, GA and FL coasts, there's nothing. 

 

there is a little tiny blip on one station in PR...but i have no idea if that's connected. 

[Ginx snewx]

it could have been an asteroid for all i know. or some fat dude doing a cannonball. but i don't flatly dismiss what the data is best suggesting.

 

if it was an offshore slump, i would think the effects would have made it into the Gulf of Maine...and been felt down along the SE coast. but once you get north of Chatham, there's nothing. and spots like Bar Harbor are just as exposed to the SE as Chatham is (for waves moving from offshore to the west).

 

likewise, if you review the data out the SC, GA and FL coasts, there's nothing. 

 

there is a little tiny blip on one station in PR...but i have no idea if that's connected. 

its odd for sure. Yea the data with the pressure couplets I posted make me believe this was gravity wave induced. I mean that radar off of the NJ coast was just intense, also remember the polar low looking visible. There were relatively light winds though recorded so hard to understand without data. 

[wxsniss]

Just saw this thread...

Made this post below on June 13... I believe this is the MCS speculated to have caused/contributed to the small tidal wave. Couldn't capture the animation, but there was impressive circulation with this system... not hard to imagine a "mini-storm surge" resulting from the circulation.
 

Sorry if posted earlier, haven't been following...

Nice mesolow off Cape with impressive circulation:

[Typhoon Tip]

Just saw this thread...

Made this post below on June 13... I believe this is the MCS speculated to have caused/contributed to the small tidal wave. Couldn't capture the animation, but there was impressive circulation with this system... not hard to imagine a "mini-storm surge" resulting from the circulation.

 

 

That's a mid-level vort-max (meso) generated by convection... That feature wasn't present quite like that at the time the MCS crossed the coastal plain -- I remember the event.  But it is impressive as others and yourself noted when it was first observed.  Also, if that was vertically integrated to the surface, any surge caused by it would have been very localized, even if it were matured over the coastal waters of the Mid A.  

 

The problem with the tsunamis idea that I have is that the pressure perturbation is so small compared to the weight of the ocean, so it doesn't add up. 

 

We're talking about a tidal variation observed at gauges up and down the eastern seaboard, all the way to PR.   This needs to be proved mathematically, is what it boils down to.  Slosh back as suggested by Forky' could certainly be a factor, and probably was an obfuscating factor to some degree around the MA.  But, not in PR. Nothing against Forky', but not outside the immediate area of the storm's force -- that's not how slosh works.  Slosh occurs when the wind blows strongly out to sea, and surface action temporarily exceeds upwelling, such that when the wind stops, the water comes back in.  There was a subtle tidal bore way outside the wind domain of the MCS, and that is what has this puzzling.  It's attractive to call this an atmosphere attributed event, but it still needs to be scientifically proven -- it can't be automatically assumed to be that given the data at large. 

 

Look at it this way, if you one reads about storm surges, NOAA states that low pressure has a negligible effect on actually elevating sea-surface heights compared to the "pile on" effect of over-abundant wave action.  If low pressures at the cores of hurricanes can't cause tsunamis, it gets harder to intuitively sea how a mere MCS, one that is also only labled as moderate in intensity, would be physically capable of doing as much.   

 

I still see a coincident geological event as plausible in this. 

[wxsniss]

That's a mid-level vort-max (meso) generated by convection... That feature wasn't present quite like that at the time the MCS crossed the coastal plain -- I remember the event.  But it is impressive as others and yourself noted when it was first observed.  Also, if that was vertically integrated to the surface, any surge caused by it would have been very localized, even if it were matured over the coastal waters of the Mid A.  

 

The problem with the tsunamis idea that I have is that the pressure perturbation is so small compared to the weight of the ocean, so it doesn't add up. 

 

We're talking about a tidal variation observed at gauges up and down the eastern seaboard, all the way to PR.   This needs to be proved mathematically, is what it boils down to.  Slosh back as suggested by Forky' could certainly be a factor, and probably was an obfuscating factor to some degree around the MA.  But, not in PR. Nothing against Forky', but not outside the immediate area of the storm's force -- that's not how slosh works.  Slosh occurs when the wind blows strongly out to sea, and surface action temporarily exceeds upwelling, such that when the wind stops, the water comes back in.  There was a subtle tidal bore way outside the wind domain of the MCS, and that is what has this puzzling.  It's attractive to call this an atmosphere attributed event, but it still needs to be scientifically proven -- it can't be automatically assumed to be that given the data at large. 

 

Look at it this way, if you one reads about storm surges, NOAA states that low pressure has a negligible effect on actually elevating sea-surface heights compared to the "pile on" effect of over-abundant wave action.  If low pressures at the cores of hurricanes can't cause tsunamis, it gets harder to intuitively sea how a mere MCS, one that is also only labled as moderate in intensity, would be physically capable of doing as much.   

 

I still see a coincident geological event as plausible in this. 

 

 

Good stuff.

 

Can we get consensus on whether there in fact was a simultaneous unidirectional and sudden tidal variation from Puerto Rico to New England? If this is true (and I gather from the thread we're still not sure), that should favor geologic over meteorologic cause. Not even a hurricane can generate that widespread and sudden a tidal variation.

 

(OT: nice 2am line of boomers here in Boston)

[Tropopause_Fold]

That's a mid-level vort-max (meso) generated by convection... That feature wasn't present quite like that at the time the MCS crossed the coastal plain -- I remember the event. But it is impressive as others and yourself noted when it was first observed. Also, if that was vertically integrated to the surface, any surge caused by it would have been very localized, even if it were matured over the coastal waters of the Mid A.

The problem with the tsunamis idea that I have is that the pressure perturbation is so small compared to the weight of the ocean, so it doesn't add up.

We're talking about a tidal variation observed at gauges up and down the eastern seaboard, all the way to PR. This needs to be proved mathematically, is what it boils down to. Slosh back as suggested by Forky' could certainly be a factor, and probably was an obfuscating factor to some degree around the MA. But, not in PR. Nothing against Forky', but not outside the immediate area of the storm's force -- that's not how slosh works. Slosh occurs when the wind blows strongly out to sea, and surface action temporarily exceeds upwelling, such that when the wind stops, the water comes back in. There was a subtle tidal bore way outside the wind domain of the MCS, and that is what has this puzzling. It's attractive to call this an atmosphere attributed event, but it still needs to be scientifically proven -- it can't be automatically assumed to be that given the data at large.

Look at it this way, if you one reads about storm surges, NOAA states that low pressure has a negligible effect on actually elevating sea-surface heights compared to the "pile on" effect of over-abundant wave action. If low pressures at the cores of hurricanes can't cause tsunamis, it gets harder to intuitively sea how a mere MCS, one that is also only labled as moderate in intensity, would be physically capable of doing as much.

I still see a coincident geological event as plausible in this.

But your sort of exaggerating an important point - it was not up and down the eastern seaboard. It was Hatteras to Chatham. With one tidal guage in PR ( of several available) also recording some sort of (perhaps unrelated) very small rise and fall.

If you look over the data...you'll see this.

[OceanStWx]

But your exaggerating an important point - it was not "up and down the east coast". It was Hatteras to Chatham. With one tidal guage in PR ( of several available) also recording some sort of (perhaps unrelated) very small rise and fall.

If you actually stop and look over the data...you'll see this.

 

I agree. I mean all we're saying is it's equally as plausible that the atmospheric and ocean waves resonated in such a way to produce some constructive interference.

[CT Rain]

That's a mid-level vort-max (meso) generated by convection... That feature wasn't present quite like that at the time the MCS crossed the coastal plain -- I remember the event.  But it is impressive as others and yourself noted when it was first observed.  Also, if that was vertically integrated to the surface, any surge caused by it would have been very localized, even if it were matured over the coastal waters of the Mid A.  

 

The problem with the tsunamis idea that I have is that the pressure perturbation is so small compared to the weight of the ocean, so it doesn't add up. 

 

We're talking about a tidal variation observed at gauges up and down the eastern seaboard, all the way to PR.   This needs to be proved mathematically, is what it boils down to.  Slosh back as suggested by Forky' could certainly be a factor, and probably was an obfuscating factor to some degree around the MA.  But, not in PR. Nothing against Forky', but not outside the immediate area of the storm's force -- that's not how slosh works.  Slosh occurs when the wind blows strongly out to sea, and surface action temporarily exceeds upwelling, such that when the wind stops, the water comes back in.  There was a subtle tidal bore way outside the wind domain of the MCS, and that is what has this puzzling.  It's attractive to call this an atmosphere attributed event, but it still needs to be scientifically proven -- it can't be automatically assumed to be that given the data at large. 

 

Look at it this way, if you one reads about storm surges, NOAA states that low pressure has a negligible effect on actually elevating sea-surface heights compared to the "pile on" effect of over-abundant wave action.  If low pressures at the cores of hurricanes can't cause tsunamis, it gets harder to intuitively sea how a mere MCS, one that is also only labled as moderate in intensity, would be physically capable of doing as much.   

 

I still see a coincident geological event as plausible in this. 

 

That's not really the issue. The only issue is getting a wave train or pressure induced perturbation of the sea height to resonate with the deep water wave. The intensity of that perturbation is somewhat irrelevant. These have been documented many times before with squall lines and can be proven mathematically. The oceanographers at Woods Hole and from the NOAA tsunami unit said they thought it was a meteotsunami.

 

It definitely doesn't look like a seiche to me. 

[Typhoon Tip]

That's not really the issue. The only issue is getting a wave train or pressure induced perturbation of the sea height to resonate with the deep water wave. The intensity of that perturbation is somewhat irrelevant. These have been documented many times before with squall lines and can be proven mathematically. The oceanographers at Woods Hole and from the NOAA tsunami unit said they thought it was a meteotsunami.

 

It definitely doesn't look like a seiche to me. 

 

 

That's an interesting point -- there could be something of a harmonic feed-back.   Constructive wave interference between the atmosphere and the ocearn. Interesting.  

 

I agree -- that's the second time you've mentioned that seiche.  I don't believe so either.  For that matter, I don't think I have ever heard of seiche in deference to oceanic phenomenon.  

 

And no Phil, I am not "exaggerating".  I am not making that up about PR, and Hat to Chat is up and down the eastern seaboard.  Stop reading in so much. It's the origin of your misconstruing the intent and starting the dumb argument yesterday.  You are not good at it and it is petty, and adversarial. 

[Tropopause_Fold]

That's an interesting point -- there could be something of a harmonic feed-back. Constructive wave interference between the atmosphere and the ocearn. Interesting.

I agree -- that's the second time you've mentioned that seiche. I don't believe so either. For that matter, I don't think I have ever heard of seiche in deference to oceanic phenomenon.

And no Phil, I am not "exaggerating". I am not making that up about PR, and Hat to Chat is up and down the eastern seaboard. Stop reading in so much. It's the origin of your misconstruing the intent and starting the dumb argument yesterday. You are not good at it and it is petty, and adversarial.

Ok.

[Ginx snewx]

dhs44 wrote:

June 27, 2013 at 1:09 PM

The water off the east coast is pretty shallow, on the order of 50 m. The tsunami velocity in 50 m is 22 m/s or 50 mph. The speed of the Derecho was about 50 mph. The derecho will be lower pressure (and winds) will move the water at the surface at a rate consistent with the speed of the storm. Because the speed of the storm is close the the tsunami velocity at that water depth, the storm will excite a long wave, which propagates as a tsunami.

These are not that rare. Looking at tide gauges in the Atlantic shows one for the 2012 derecho. In addition, a "surge" was observed (but not reported) in lake erie. The tide gauge data is publically available.

this was posted elsewhere

[Tropopause_Fold]

What, to me, rules out offshore slumping is the lack of water rise along the Jersey shore where the brunt of the MCS pushed offshore. Had it been something offshore / underwater propagating westward...I would think places like Sandy Hook and the Battery would have registered sharp rise due to the shape of the coastline and natural channeling effect in that area. Likewise, the lack of rise/fall south of Hatteras, where the land bends dramatically westward, suggests that it was blocked from the wave(s). Also...if you just follow the timeline of the water rise/fall at each location you can see a nice west to east movement.

[CT Rain]

That's an interesting point -- there could be something of a harmonic feed-back.   Constructive wave interference between the atmosphere and the ocearn. Interesting.  

 

I agree -- that's the second time you've mentioned that seiche.  I don't believe so either.  For that matter, I don't think I have ever heard of seiche in deference to oceanic phenomenon.  

 

And no Phil, I am not "exaggerating".  I am not making that up about PR, and Hat to Chat is up and down the eastern seaboard.  Stop reading in so much. It's the origin of your misconstruing the intent and starting the dumb argument yesterday.  You are not good at it and it is petty, and adversarial. 

 

That's how these form. If it was just wind/pressure differences you'd get a tsunami from every hurricane. It's the resonance of the wave that can lead to the tsunami. 

[Typhoon Tip]

That's how these form. If it was just wind/pressure differences you'd get a tsunami from every hurricane. It's the resonance of the wave that can lead to the tsunami. 

 

Have you ever heard of the the Tacoma -Narrows bridge event.  I'm sure you have, but this reminds of that.  It was only 40kt wind causing all that, and it was resonance run amuk!

[Ginx snewx]

What needs to be explained is why this sloshing of the basin continued well into the night. this Montauk point graph shows how the water was sloshing around all night. I understand the Meteo tsunami initial wave but this seems highly unusual.

[Ginx snewx]

This is pretty awesome

http://www.theplasmaverse.com/pdfs/meteorological-tsunamis-destructive-atmosphere-induced-waves-observed-in-the-worlds-oceans-seas-seiches-abiki-milghuba.pdf